Tandem stroller frame



FIG. 1 is a front elevational view of a tandem stroller frame showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front, right perspective view thereof;

FIG. 8 is perspective view for reference, showing that two chair frames are mountable on top of the tandem stroller frame of my new design; and,

FIG. 9 is perspective view for reference, showing that the chair frames and the tandem stroller frame are foldable into a stowed position.

The broken lines illustrate the environment elements of the tandem stroller frame and form no part of the claimed design. 

The ornamental design for a tandem stroller frame, as shown and described. 